CHY2F (JAN09CHY2F01) General Certifi cate of Secondary Education January ADDITIONAL SCIENCE Unit Chemistry C2. CHEMISTRY Unit Chemistry C2

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1 Surname Other Names For Examiner s Use Centre Number Candidate Number Candidate Signature General Certifi cate of Secondary Education January 2009 ADDITIONAL SCIENCE Unit Chemistry C2 CHEMISTRY Unit Chemistry C2 CHY2F F Foundation Tier Thursday 15 January 2009 For this paper you must have: a ruler the Data Sheet (enclosed). You may use a calculator. Time allowed: 45 minutes 1.30 pm to 2.15 pm For Examiner s Use Question Mark Question Mark Instructions Use black ink or black ball-point pen. Fill in the boxes at the top of this page. Answer all questions. You must answer the questions in the spaces provided. Answers written in margins or on blank pages will not be marked. Do all rough work in this book. Cross through any work you do not want to be marked. Information The maximum mark for this paper is 45. The marks for questions are shown in brackets. You are expected to use a calculator where appropriate. You are reminded of the need for good English and clear presentation in your answers. 5 6 Total (Column 1) Total (Column 2) TOTAL Examiner s Initials Advice In all calculations, show clearly how you work out your answer. (JAN09CHY2F01) G/K /6/6/6 CHY2F

2 2 Answer all questions in the spaces provided. 1 This barbecue burns propane gas. Barbecue Propane gas cylinder The diagram represents a propane molecule. H H H H C C C H H H H 1 (a) What is the formula of propane?... 1 (b) (i) Draw a ring around the name of the particle represented by the symbols and in the diagram. electron neutron proton (02)

3 3 1 (b) (ii) Draw a ring around the type of bonding that holds the atoms together in a propane molecule. covalent ionic metallic 1 (c) Under high pressure in the cylinder propane is a liquid. Liquid propane evaporates easily to form a gas when the tap on the cylinder is opened. Draw a ring around the correct answer in each box to explain why propane evaporates easily. Propane has a high low boiling point because it consists of large small molecules. 4 Turn over for the next question Turn over (03)

4 4 2 A student heated some hydrated copper sulfate crystals. The equation for this reaction is shown below. CuSO 4.5H 2 O (s) hydrated copper sulfate crystals The diagram shows the apparatus used. CuSO 4 (s) anhydrous copper sulfate + 5H 2 O (l) water Hydrated copper sulfate crystals Vapour Heat Ice cube Liquid A 2 (a) Name liquid A... 2 (b) What helped the vapour to condense into liquid A? 2 (c) Put a tick ( ) next to the correct meaning of the symbol Meaning ( ) equal amounts of reactants and products exothermic reaction reversible reaction (04)

5 5 2 (d) The student weighed the copper sulfate before and after it was heated. The experiment was repeated and the two sets of results are shown in the table. Mass of copper sulfate before heating in grams Mass of copper sulfate after heating in grams Mass lost in grams (d) (i) Draw a ring around the average mass lost for these two sets of results g 0.87 g 0.89 g 2 (d) (ii) The student used the same mass of copper sulfate each time but the mass lost was different. Put a tick ( ) next to the two reasons which could explain why the mass lost is different. Reason ( ) The student used different test tubes for the two experiments. The student made errors in weighing during the experiments. The student used more ice in one of the experiments. The student did not heat the copper sulfate for long enough in one of the experiments. (2 marks) 2 (e) Anhydrous copper sulfate is used to test for water. Use words from the box to complete the sentence. blue green red white Water changes the colour of anhydrous copper sulfate from... to.... (2 marks) 8 Turn over (05)

6 6 3 This label was on a container of graphite lubricant. Super G Graphite Lubricant Super G forms a thin anti-friction film on metal surfaces. It provides good lubrication when metal parts rub against each other. 3 (a) Give one reason why a lubricant is used when metal parts rub against each other. 3 (b) The diagram shows the arrangement of atoms in graphite. Layers of atoms 3 (b) (i) Draw a ring around the type of atoms in graphite. aluminium carbon silicon (06)

7 7 3 (b) (ii) Graphite is a good lubricant because it is slippery. Use the diagram to explain why graphite is slippery (2 marks) 4 Turn over for the next question Turn over (07)

8 8 4 The following steps show how to use a type of glue. Step 1 Measure out equal amounts of the liquids from tubes A and B. Tube B Tube A Step 2 Mix the liquids to make the glue. Put a thin layer of the glue onto each of the surfaces to be joined. Glue Step 3 Assemble the pieces to be joined and then hold them together with tape. Tape Step 4 Leave the glue to set. 4 (a) When liquids A and B are mixed a chemical reaction takes place. 4 (a) (i) This reaction is exothermic. Complete the sentence below using a word or phrase from the box. decrease increase stay the same During the reaction the temperature of the mixture will.... (08)

9 9 4 (a) (ii) When the glue sets it forms a giant covalent structure. Draw a ring around one property that you would expect the set glue to have. good conductor of electricity low melting point high melting point 4 (b) The time taken for the glue to set at different temperatures is given in the table below. Temperature in C Time taken for the glue to set 20 3 days 60 6 hours 90 1 hour 4 (b) (i) Complete the sentences below using words or phrases from the box. decreases increases stays the same When the temperature is increased the time taken for the glue to set.... When the temperature is increased the rate of the setting reaction.... (2 marks) 4 (b) (ii) Put a tick ( ) next to the two reasons why an increase in temperature affects the rate of reaction. Reason ( ) It gives the particles more energy. It increases the concentration of the particles. It increases the surface area of the particles. It makes the particles move faster. (2 marks) Turn over 6 (09)

10 10 5 Electrolysis can be used to remove unwanted hair from the skin. Positive electrode Power supply Negative electrode Hair Body fluid Hair follicle The positive electrode is connected by a patch to the skin. The negative electrode is connected to the hair. The body fluid is a solution that contains sodium chloride. The electricity causes the electrolysis of a small amount of this solution. 5 (a) In this solution hydrogen ions move to the negative electrode. Complete the sentence using one word from the box. negative neutral positive Hydrogen ions move to the negative electrode because they have a... charge. 5 (b) Draw a ring around the name of the gas produced at the positive electrode during the electrolysis of sodium chloride solution. chlorine hydrogen nitrogen (10)

11 11 5 (c) The electrolysis of the sodium chloride solution forms a strong alkali around the hair follicle. 5 (c) (i) Complete the name of this strong alkali using one of the words from the box. chloride hydroxide nitrate The name of this strong alkali is sodium (c) (ii) Suggest how this strong alkali helps to remove the hair Turn over for the next question Turn over (11)

12 12 6 Read the article and then answer the questions that follow. Nanotennis! Tennis balls contain air under pressure, which gives them their bounce. Normal tennis balls are changed at regular intervals during tennis matches because they slowly lose some of the air. This means that a large number of balls are needed for a tennis tournament, using up a lot of materials. Nanocoated tennis balls have a nanosize layer of butyl rubber. This layer slows down the escape of air so that the ball does not lose its pressure as quickly. The nanocoated tennis balls last much longer and do not need to be replaced as often. 6 (a) How does the nanosize layer make the tennis balls last longer? (12)

13 13 6 (b) Put a tick ( ) next to the best description of a nanosize layer. Description ( ) A layer one atom thick. A layer a few hundred atoms thick. A layer millions of atoms thick. 6 (c) Suggest why using nanocoated tennis balls would be good for the environment. (2 marks) 4 Turn over for the next question Turn over (13)

14 14 7 Iron is an essential part of the human diet. Iron(II) sulfate is sometimes added to white bread flour to provide some of the iron in a person s diet. 7 (a) The formula of iron(ii) sulfate is FeSO 4 Calculate the relative formula mass (M r ) of FeSO 4 Relative atomic masses: O = 16; S = 32; Fe = 56. The relative formula mass (M r ) =... (2 marks) 7 (b) What is the mass of one mole of iron(ii) sulfate? Remember to give the unit (c) What mass of iron(ii) sulfate would be needed to provide 28 grams of iron? Remember to give the unit (14)

15 15 8 This question is about oxygen atoms. The periodic table on the Data Sheet may help you to answer this question. 8 (a) (i) Oxygen atoms have 8 electrons. Complete the diagram to represent the arrangement of electrons in an oxygen atom. Use crosses ( ) to represent the electrons. A 8 (a) (ii) Name the part of the oxygen atom that is labelled A on the diagram (b) Two isotopes of oxygen are oxygen-16 and oxygen O oxygen O oxygen-18 Explain, in terms of particles, how the nucleus of an oxygen-18 atom is different from the nucleus of an oxygen-16 atom. (2 marks) 4 Turn over (15)

16 16 9 Read the information below and then answer the questions that follow. It was once thought that organic compounds could be made only in living organisms. The living organisms were assumed to have a special life force. This life force allowed them to make organic compounds. Urea is an organic compound produced in animals. It is found in urine. In 1828, Friedrich Wöhler made urea from chemicals which were not obtained from living things. Other famous scientists still believed in the idea of a life force. Wöhler made another organic compound in Most scientists then stopped believing that a life force was needed to make organic compounds. 9 (a) How did Wöhler prove that a life force is not needed to make organic compounds? 9 (b) Suggest why in 1828 most scientists continued to believe that a life force was needed to produce an organic compound. (16)

17 17 9 (c) Suggest why in 1845 most scientists stopped believing that a life force was needed to make an organic compound. 9 (d) Some scientists repeated Wöhler s experiment. These scientists used lead nitrate as one of their starting materials. Lead nitrate solution can be made by reacting lead with an acid. 9 (d) (i) Give the name of this acid (d) (ii) State how solid lead nitrate can be obtained from lead nitrate solution (e) The equations below show two methods of making urea. Method 1 (Wöhler s method) Pb(NO 3 ) 2 + 2KCNO + 2NH 3 + 2H 2 O 2KNO 3 + Pb(OH) 2 + 2(NH 2 ) 2 CO urea Method 2 (The modern industrial method) 2NH 3 + CO 2 (NH 2 ) 2 CO + H 2 O urea Method 2 has a higher atom economy than method 1. Use information from the equations to explain why. (2 marks) END OF QUESTIONS 7 (17)

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21 4421/63/DS Data Sheet 1. Reactivity Series of Metals Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Tin Lead Hydrogen Copper Silver Gold Platinum most reactive least reactive (elements in italics, though non-metals, have been included for comparison) 2. Formulae of Some Common Ions Positive ions Name Formula Negative ions Name Formula Hydrogen Sodium Silver Potassium Lithium Ammonium Barium Calcium Copper(II) Magnesium Zinc Lead Iron(II) Iron(III) Aluminium H + Na + Ag + K + Li + NH 4 + Ba 2+ Ca 2+ Cu 2+ Mg 2+ Zn 2+ Pb 2+ Fe 2+ Fe 3+ Al 3+ Chloride Bromide Fluoride Iodide Hydroxide Nitrate Oxide Sulfide Sulfate Carbonate Cl Br F I OH NO 3 O 2 S 2 SO 4 2 CO 3 2 Turn over January 2009 Insert for GCSE Additional Science (CHY2) and GCSE Chemistry (CHY3) Question Papers

22 3. The Periodic Table of Elements Li lithium 3 23 Na sodium K potassium Rb rubidium Cs caesium 55 [223] Fr francium 87 9 Be beryllium 4 24 Mg magnesium Ca calcium Sr strontium Ba barium 56 [226] Ra radium Sc scandium Y yttrium La* lanthanum 57 [227] Ac* actinium 89 Key relative atomic mass atomic symbol name atomic (proton) number 48 Ti titanium Zr zirconium Hf hafnium 72 [261] Rf rutherfordium V vanadium Nb niobium Ta tantalum 73 [262] Db dubnium Cr chromium Mo molybdenum W tungsten 74 [266] Sg seaborgium Mn manganese 25 [98] Tc technetium Re rhenium 75 [264] Bh bohrium 107 H 1 hydrogen 1 56 Fe iron Ru ruthenium Os osmium 76 [277] Hs hassium Co cobalt Rh rhodium Ir iridium 77 [268] Mt meitnerium Ni nickel Pd palladium Pt platinum 78 [271] Ds darmstadtium Cu copper Ag silver Au gold 79 [272] Rg roentgenium 111 Zn 65 zinc Cd cadmium Hg mercury B boron 5 27 Al aluminium Ga gallium In indium Tl thallium C carbon 6 28 Si silicon Ge germanium Sn 50 tin 207 Pb lead N nitrogen 7 31 P phosphorus As arsenic Sb antimony Bi bismuth 83 Elements with atomic numbers have been reported but not fully authenticated 16 O oxygen 8 32 S sulfur Se selenium Te tellurium 52 [209] Po polonium F fluorine Cl chlorine Br bromine I iodine 53 [210] At astatine 85 He 4 helium 2 20 Ne neon Ar argon Kr krypton Xe xenon 54 [222] Rn radon 86 * The Lanthanides (atomic numbers 58 71) and the Actinides (atomic numbers ) have been omitted. Cu and Cl have not been rounded to the nearest whole number.